Clarence e



c. E. nom'm. METHOD-0F ExcmuG xmAY TUBES.

APPLICATION FILED DEC-16. I913;

1,194,071. PatntedAugQS, 1916.

" 'Elkhart, in the county of Elkhart and State TE STATES E CLARENCE E. ROI-IRER, F ELKHART, INDIANA, ASSIGNOR TOSCHEIDEL-WESTEBN .X-BAY COIL (30., OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

rim-Hon or EXCITING- XI-RAY TUBES.

To all whom it mag concern: w I

Be it known that I, CLAnENoE E.- Romain, a citizen of the United States, residing at of Indiana, have invented certain new and useful Improvements in Methods of Exciting rX-Rayjl ub es, of which the following 1s I a s ecificatlo i and appropriating and directing the unidirectional impulses arisingfrom such cyne of thg bjects ofmy invention is to improve X-rayi apparatus to the end that lie-operative efficiency is enhanced; the ca-.

acity' of the tube increased and its. durag ity, or useful life is pr l Another object 0 my invention is to provide an apparatus, for the economical utilization of high potential. alternating electric current, by rectifying selected cycles thereof cles, or parts thereof, from the alternating circuit into a derived circuit containing-the tube and discarding, withoutrectifying, intermediate cycles, whereby providing a series of strong, undulating uni-directional impulses capable of effecting an intense cathode stream, by their forceful impacts against the target of the tube producing maximum X-ray penetration an definition.

X In using an X-ray, tube it is necessary that thecurrent shall pass in onedirection, only, through the tube so that the cathode stream will not be interfered with by the passage whieh would set up inverse current efiects in the tube and destroy its effectiveness.

It has, heretofore, been customary to se- Y of electric current in the opposite direction,

lect a small'fraction of each wave, usually the crest of the wave of a given polarity of each and every cycle of an alternating, high potential current and to'entirely discard-all waves of the opposite polarity without rec--v of the alternating current.

tifying any part By this means a very small percentage the entire current is employed for useful purposes.

In systems of thischaracter, in which only the crest of the succeeding waves'of a given polarity are taken for useful work the tubey a single circuit only is necessary, the' tube being includedin said circuit in. direct series relation with the source of alternatinipurrent supply,

my apparatus both waves, or fractions Specification of Letters Patent. Patented Aug, 8, 1916 Application filed December 16, 1913. serial m 806,985.

thereof, of given, or selected cycles are utilized, and intermediate cycles are rejected.

In making the entire cycle available for X-ray purposes, it is necessary that the current impulses be rectified, or that the direction of current. of one wave impulse be changed to coincide with the direction of the a the alternating current circuit, which latter contains the source of alternating current supply and in which alternating current cycles are produced, I employ a cycle selector and current rectifier whereby cycles are selected and then rectified'into current impulses of uni-directional character, which are conducted into'the direct currentcircuit, and by which intermediate cycles are rejected', and not rectified. Thus every alter- .nating cyclemay be appropriated or every alternate cycle'may be selected for useful work and therespective intermediate cycles discarded or one alternation or half cycle may be taken and three intermediate alternations rejected. This spacing of the -unidirectional current impulses produces better X-rayefi'ects than may be produced when every cycle is rectified and appropriated, as the eii'ect in the tube is all that can be de- "sired and the elimination of certain of the 'invention'may be carried out. Fig. 2' is a diagrammatic representation of alternating current waves with every other cycle elimihated, and; Fig. 3"is a similar view with groups of three alternations eliminated out of every two cycles.

' The cycle selector is preferably composed of. two disks A and B, of insulating material such as. mica, adjustably mounted on a shaft 7 O which is driven in synchronism with the c rrent alternations or preferablyv by a syngrees of its periphery, an electric connector segment 11 and 11',.respectively. They are disposed on opposite sides of the diameter of the disks and extend over such portion of the circumference of the disks as may-be necessary to rectify the amount of the current wave that it is necessary to employ.

When the disks are rotated in synchronism with the alternations of the current, as

they must be, they will make one revolution to each two cycles or four alternations of the current, and each wave, of every cycle, is operated upon, and thus a series of unidirectional impulses, corresponding with the number of waves, of the selected cycles will be collected and available for the tube.

Assuming that the positive wave comes from the secondary coil S over the wire 9, it will pass to collector 1' over wire 5 to the connector 11 of diskB, thence to collector 2' and over wire 12,in the direction of the arrow-to the cathode terminal of the tube. From the anode terminal of the tube, over wires 13 and 8 to collector 4; over connector 11 to collector 3, thence over wire 7 to wire 10 and to the secondary coil S. The next positive impulse will come from coil S over wire 10 to collector 3, by this time the disks have made one quarter revolution and the connectors 11-ll are in dotted line position. Current will thenflow from collector 3 over connector 1ldotted lin e-to collector 2', thence through the tube to collector l, connector 11dotted line-to collector 1 and over wires 5 and 9 to coil S. The next, or third positive wave or alternations will come in at 1 pass to 2, thence over wire 6 to the tube and back over wires 8 to 4 over 11' to 3 and thence to S The fourth wave will come in at 3 over 11 to 2, over 6 to tube, thence over 8 to 4, over 11 to 1' and back to S, thus rectifying tyvo cycles at each revolution.

Suppose that we eliminate collector 2 by opening switch 12, then collector 2 is dead and one complete cycle will be rejected or discarded and the-current will be such as diagrammatically represented in Fig. 2 in which every alternate cycle is appropriated ,and rectified and intermediate cycles are discarded, as-shown by the arrows. It is obvious that switch 12 may be .11 to whichever collector they are included in circuit as by opening. 7

switches 20 or 21, then the direct current impulses, appearing in the direct current circuit, would be fairly represented by diagram Fig. 3 where one alternation is selected and rectified and three intermediate 7 alternations are discarded. Under such circumstances current in the tube circuit could, only pass from collector 4' over connector 1,or 3, is left connected in circuit. If desired other disks could be added and greater variations than those specifically disclosed herein could be produced. V

The illustrated exemplification is thought to be sufficient for a clear disclosure of m invention "without further elaboration, as realize that changes'maybe made in the size, number and disposition of parts within the scope of the appended claims, withoutdeparting from the spirit of my invention';.

Having described my invention, what I claim is:-'

1. The combination with a transformer, an X-ray tube, and a motor driven shaft,

of a palr of disks of insulating material mounted in spaced relation on said shaft, a.

metallic segment on each disk in diametri cally opposite position, a pair of diametrically opposite. collector brushes for each i disk, the brushes of one pair being inflaxial 10c alinement with those of the other pair, circuits connecting adjacent brushes of each pair to one of the secondary terminals of the transformer and the opposite adjacent brushes to the other secondary terminal, a 10s secondpair of collector brushes for each disk positioned at approximately 90 degrees I to the first pair, circuits connecting adjacent brushes of each second mentioned pairs to oneterminal of the. X-ray tube and the opposite adjacent brushes of'the second mentioned pairsto the other terminal of the X-ray tube and means for disconnecting one of said brushes from its associated terminal.

2. The combination with a transformer, an X-ray tube. and a motor driven shaft, of a pair of disks of insulating material mounted in spaced relation on said shaft, a.

metallic segment on each disk in diametrically opposite position, a' pair of diametrically opposite collector brushes for each disk, the brushes of one pair being in axial alinement with those of the otherpair, circuits connecting adjacent brushes of each pair to one of the secondary terminals of the transformerand the opposite adjacent brushes to the other secondary terminal, a. second pair of collector brushes for each disk positioned at approximately 90 degrees 18 to the first pair, circuits connecting adja cent brushes of each second mentioned pairs to one terminal of the X-gray tube and the opposite, adjacent brushes of the second mentioned pairs to the othenterminal of the means for disconnecting "one X-my tube, of the brushes from a terminal of the Xray; tube,and means for disconnecting one of the brushes from its connection with a secondary terminal of the transformer. 11

Intestimony whereof I hereunto set my I hand in the presence of two witnesses.

' CLARENCE E ROHRER. In the presence of ETHEL'R. BEARDSLEY, MAUDE F. SOKIPTURE. 

